Submission #107273

#	Time	Username	Problem	Language	Result	Execution time	Memory
107273		abil	Split the sequence (APIO14_sequence)	C++14	11 / 100	79 ms	9320 KiB

sequence

#include <bits/stdc++.h>

using namespace std;

const int N = (int)100007;

int n, k, par[207][N];
long long dp[3][N];
int arr[N];
long long f(int l,int r){
      return arr[l] * (arr[r] - arr[l]);
}
void solve(int g,int l,int r,int optl,int optr){
      if(l > r){
            return;
      }
      int mid = (l + r) >> 1, opt;
      for(int i = optl; i <= min(optr,mid - 1); i++){
            if(dp[(g % 2)][mid] <= dp[(g - 1) % 2][i] + f(i,mid)){
                  dp[(g % 2)][mid] = dp[(g - 1) % 2][i] + f(i,mid);
                  opt = i;
            }
      }
      par[g][mid] = opt;
      solve(g,l,mid - 1, optl, opt);
      solve(g,mid + 1, r, opt, optr);
}
main(){
      scanf("%d %d",&n, &k);
      for(int i = 1;i <= n; i++){
            scanf("%d", &arr[i]);
            arr[i] = arr[i - 1] + arr[i];
      }
      for(int i = 1;i <= k; i++){
            solve(i,1,n,1,n - 1);
      }
      printf("%lld\n",dp[(k % 2)][n]);
       while (k > 0 && n > 0) {
        printf ("%d ", par[k][n]);
        n = par[k][n];
        k--;
    }
}
/*
7 3
4 1 3 4 0 2 3
*/

Compilation message (stderr)

sequence.cpp:28:6: warning: ISO C++ forbids declaration of 'main' with no type [-Wreturn-type]
 main(){
      ^
sequence.cpp: In function 'int main()':
sequence.cpp:29:12: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
       scanf("%d %d",&n, &k);
       ~~~~~^~~~~~~~~~~~~~~~
sequence.cpp:31:18: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
             scanf("%d", &arr[i]);
             ~~~~~^~~~~~~~~~~~~~~
sequence.cpp: In function 'void solve(int, int, int, int, int)':
sequence.cpp:25:12: warning: 'opt' may be used uninitialized in this function [-Wmaybe-uninitialized]
       solve(g,l,mid - 1, optl, opt);
       ~~~~~^~~~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 11 / 11
• Subtask 2: 0 / 11
• Subtask 3: 0 / 11
• Subtask 4: 0 / 17
• Subtask 5: 0 / 21
• Subtask 6: 0 / 29